In many fields and contexts, of which a few have been mentioned above as examples, it is normally necessary to transfer a fluid, such as a more or less thin fluid or a gas or a mixture thereof, from one place, such as a process or storage unit, for instance a vessel or bag of a conventional type or of a now more common disposable type or other equipment, to another place, without the fluid risking to be contaminated with foreign particles, especially airborne bacteria and the like or gaseous air pollutants.
In the fields/contexts above, there is, inter alia, a more or less continuous need for sampling of fluids, for instance for microbiological control, cell counting and other chemical analyses, or supply of regulating or active substances, such as a pH buffer or a biological starter culture, in certain process steps in the manufacture of products in the respective fields.
Whenever a new connection for the above purposes has to be made to transfer the fluid from one place to another, there is, especially in non-sterile environments, a great risk of contamination of the fluid.
Such connection can occur by introducing a sterile needle, which is connected to one vessel via a tube or pipe, into a sterile membrane connected to the other vessel. In the connecting operation, the connecting components and/or the fluid are exposed to the risk of being contaminated with airborne bacteria, spores etc. and by incorrect handling of the connecting components.
To reduce the risk of contamination when interconnecting two or more process or storage units for transfer of a fluid between them, there has been suggested, instead of the above-described needle connecting device, inter alia according to U.S. Pat. No. 3,909,910 a sterile connector for interconnecting the ends of elongate elements such as tubes or pipes by at least two cooperating connecting means each having an inlet for the associated end and an outlet for connection to each other. The connector has sealing means, which are arranged on the connecting means around the outlets and are provided with protective means in the form of thin films or foils which cover the sealing means and the outlets and are removable in the final interconnection. With the connecting means arranged end-to-end against each other with the outlets opposite each other and with the sealing means pressed against each other, by means of, for instance, a spring-loaded clamp, under elastic deformation, the protective means engaging each other are manually pulled off at the same time from the connecting means.
When pulling off the protective means, they are folded back upon themselves, and even if they are very thin there occurs in the folding area a small gap with a width corresponding to the width of the protective means. This gap “moves” in the pull-off direction and passes the area of the outlets in the sealing means and the connecting means, so that airborne contamination is entrained by the gap and risks entering the outlets and contaminating the fluid.